<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>
	
</body>
</html>
<script>
	//sessionStorage 存储某个特定的会话的数据，当浏览器关闭时数据会被清理掉
     
     //用法同localStorage
	console.dir(sessionStorage);
	console.dir(localStorage);

	sessionStorage.a = 20;

</script>